- I
have taken off the wallpaper and the surface
isn't good enough to paint. What can be done?
- What is Blown
Plaster?
- My
Ceiling is Sagging and/or Cracks are
appearing. Why?
- Can Artex be skimmed
over to make walls and/or ceilings smooth
again?
- How long do I have to
wait after plastering to paint?
I have taken off
the wallpaper and the surface isn't good enough
to paint. What can be done?
If the Plaster is sound and just needs to be made
smooth ready for painting then it can be sealed and
Re-skimmed, (PVA and a thin coat of plaster over the
existing).
If the plaster is loose (Blown) it will have to be
taken back to where the trouble is. Sometimes just
the original skim coat has blown so only that has to
come off, but sometimes the backing coat has become
loose so it has to be taken back to the brickwork. In
either case the wall has to then be made dust free by
brushing and applying a coat of sealer called PVA
prior to re-plastering.
This is plaster that doesn't have contact with the
brick wall anymore and is just managing to hang onto
the wall. It can be recognized by knocking with your
fingers. You will hear a louder / hollow sound on the
blown plaster than in the healthy plaster. Blown
plaster should be knocked out and patched up to bring
it level with the sound plaster before re-skimming.
It could be just the skim (The smooth thin top
coat) that has blown so only that would have to come
off before re-skimming.
Sagging in plaster boarded ceilings is usually due
to a leak above and the board has been damaged by the
water. The best course of action is to remove the
damaged board and replace, PVA the rest of the
ceiling and skim the whole ceiling which will allow
the patch to be joined properly using a mesh scrim
over the join to stop it cracking.
Sagging in Lath and plaster ceiling is where the
sand and cement coat has come away from the laths.
This has to be removed and repaired by either
re-rendering over the laths or plaster boarding and
then skimming over the whole ceiling.
Depending on the amount of damage sometimes is is
better to replace the whole ceiling.
If the Artex is sound and clean, it can be scraped
back, sealed and skimmed over.
If the Artex is loose it will have to come off.
New plaster can only be as strong as the background
it is applied to.
Sometimes the best course of action with a ceiling
is to over board and then skim.
When skimming on top of old plaster or
plasterboard, you should wait 5-6 days before
applying a thinned coat and then 1 or 2 normal coats
of paint. If your room has been plastered from the
brick, the normal drying time is 10-14 days. In both
cases, it will help if you leave windows open. New
plaster will take on a light pink colour which tells
you it's ready to start painting.